Autonomous underwater vehicles (AUVs) are increasingly being used to collect physical, chemical, and biological information in the marine environment. Recent efforts have been made to merge AUV technology with acoustic telemetry to provide information on the distribution and movements of marine fish. During 2010, we conducted a study in coastal waters near Juneau, Alaska to determine the feasibility of using AUVs to locate marine species under rigorous field conditions, and to compare this approach with traditional vessel-based tracking. Tracking surveys were conducted with a REMUS 100 AUV equipped with an integrated acoustic receiver and hydrophone. The AUV was programmed to navigate along predetermined routes to detect acoustic transmitters within the area. Comparable surveys were conducted with a boat equipped with acoustic tracking gear. Moorings with transmitters at 20-500 m were deployed to provide acoustic targets at known locations and depths. Marine fishes and crabs were tagged to provide mobile targets. Transmitter depth had a major impact on tracking performance. The AUV was equally effective or better detecting reference transmitters in shallow water, and significantly better than the boat for transmitters at deeper depths. Similar results were observed for the tagged animals. Crabs at moderate depths were recorded by both tracking methods, while only the AUV detected fish at depths exceeding 500 m. The AUV periodically had difficulty navigating and maintaining course due to the strong currents and extreme depths in the area. AUVs with greater cruising speeds, increased operating depths, and improved navigation would enhance AUV performance in marine environments.

Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O. tshawytscha) and chum (O. keta) salmon to the Yukon River, Kuskokwim River, and Norton Sound areas of Alaska prompted the state of Alaska to restrict commercial and subsistence fisheries during 2000 and declare the region a fisheries disaster area. Weak salmon returns to these river systems follow several years of low sockeye (O. nerka) salmon returns to Bristol Bay, which was declared a fisheries disaster region during 1998 by both the State of Alaska and the U.S. Department of Commerce. Causes of the poor salmon returns to these river systems are not known however, the regional-scale decline of these stocks indicates that the marine environment may play a critical role. Ocean conditions, particularly in the first few months after the salmon leave fresh water, are known to significantly affect salmon survival (Holtby et al. 1990; Friedland et al. 1996; Beamish and Mahnken 2001). Mechanisms affecting marine survival of the eastern Bering Sea salmon stocks are unknown, principally due to the lack of marine life history information on western Alaska salmon. To improve understanding of the marine life-history stage of salmon in the Bering Sea, the North Pacific Anadromous Fish Commission (NPAFC) began an internationally coordinated research program on salmon in the Bering Sea called the Bering-Aleutian Salmon International Survey (BASIS) (NPAFC 2001). As part of BASIS, scientists from the National Marine Fisheries Service (NMFS), Ocean Carrying Capacity (OCC) program conducted a fall survey on the eastern Bering Sea shelf to provide key ecological data for eastern Bering Sea salmon stocks during their juvenile life-history stage. The goal of the OCC/BASIS salmon research cruise was to understand mechanisms underlying the effects of environment on distribution, migration, and growth of juvenile salmon on the eastern Bering Sea shelf. Primary objectives of BASIS include: 1) to determine the extent of offshore migrations of juvenile salmon from rivers draining into the eastern Bering Sea, 2) to describe the physical environment of the eastern and northeastern Bering Sea shelf occupied by juvenile salmon, and 3) to collect biological information on other ecologically important species. Summaries of previous Bering Sea juvenile salmon research cruises can be found in Farley et al. (1999, 2000, 2001, 2002, 2004, 2005).

The Resource Assessment and Conservation Engineering Division (RACE) of the Alaska Fisheries Science Center (AFSC) conducts bottom trawl surveys to monitor the condition of the demersal fish and crab stocks of Alaska. These data include catch per unit effort for each commercially important crab species at a standard set of stations in the eastern Bering Sea. This is a subset of the main database. Excluded are certain non standard tows and other types of data collected other than species id, species size category, species catch per unit effort (number per square nautical mile), water temperature and depth.

This is data from a long-term monitoring project which utilized sonic tags to follow aggregations of red king crab in Womens Bay near Kodiak Alaska. The database consists of four major tables: Sonic tags: An inventory of all tags used recording crab size and sex dates of tag release and recovery, and if possible the reason for tag loss. Locations: Field locations in latitude, longitude, and depth for sonic tags, generally acquired on a weekly basis. Dive summary:A summary of dive observations on sonic tagged crab aggregations to document crab behavior and habitat use. Crab measurements:Measurements of crab carapace lengths, sex, and shell conditions of diver-collected crab from crab aggregations associated with tagged crab.

This dataset is part of a laboratory experiment, which evaluated how varying prey densities (year-0 blue king crabs) and habitat type (shell and sand) affect the functional response of year-1 blue king crabs, crypsis of prey crabs, and foraging behavior of predator crabs. The data includes date, experimental duration, tank number, predator species, prey species, predator size, substrate type, initial and final prey densities, number of prey eaten, crypsis indices, survival, and time spent foraging.

This dataset is part of a laboratory experiment, which evaluated how varying ratios of prey species (year-0 blue and red king crabs) and habitat type (shell and cobble) affect prey preference of year-1 red king crabs. The data includes experimental duration, tank number, predator species, prey species, substrate type, initial and final prey densities, number of prey eaten, crypsis indices, and survival.

This dataset contains detailed crab data collected from the annual NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the eastern Bering Sea continental shelf. The standard survey area, surveyed each year since 1975, encompasses a major portion of the eastern Bering Sea shelf between the 20 meter and 200 meter isobaths and from the Alaska Peninsula to the north of St. Matthew Island. The study area is divided into a grid with cell sizes of 20 x 20 nautical miles (37 x 37 kilometers). Sampling takes place within each 20 x 20 nautical mile grid cell. In areas surrounding St. Matthew (1983-present) and the Pribilof Islands (1981-present), grid corners were also sampled to better assess king crab concentrations. In 1975, tows were 1 hour in duration; from 1976 to present, each tow is one-half hour in duration, averaging 1.54 nautical miles (2.86 kilometers) - exact tow duration and distance fished for each haul can be found in RACEBASE.HAUL. 100% of the catch is sorted for red, blue, and golden king crab, bairdi Tanner, snow crab, hybrid Tanner, and hair crab. Crabs are sorted by species and sex, and a sample is measured to the nearest millimeter to provide a size-frequency distribution (see note under use constraints for analyzing catches where crab were subsampled for measurement). Carapace width is measured for Tanner crabs, and carapace length is measured for king and hair crabs.

These are data from a laboratory experiment in which wild caught male Tanner crab (Chionoecetes bairdi) from Stephens Passage, SE Alaska were held to evaluate crab survival while harboring Hematodinium sp., a parasitic dinoflagellate and causative agent of Bitter Crab Syndrome (BCS). In October 2014, Tanner crab in various condition states were targeted and collected. Targeted crab condition states were visually healthy, visually BCS positive or questionably BCS positive. Crab were held from capture until death (ongoing) and crab were tested regularly for parasite presence using two methods, blood smears and a PCR assay to detect the presence of parasite DNA. The data include crab morphometrics, disease status by diagnostic method, and crab survival duration.

This data set is the results of a laboratory experiment. Juvenile red king crab and Tanner crab were reared in individual containers for nearly 200 days in flowing control (pH 8.0), pH 7.8, and pH 7.5 seawater at ambient temperatures (range 4.4-11.9 C). Survival, growth, and morphology were measured throughout the experiment. At the end of the experiment, calcium concentration was measured in each crab and the dry mass and condition index of each crab were determined.

This data set is the results of a laboratory experiment. Juvenile red king crab and Tanner crab were reared in individual containers for nearly 200 days in flowing control (pH 8.0), pH 7.8, and pH 7.5 seawater at ambient temperatures (range 4.4-11.9 C). Survival, growth, and morphology were measured throughout the experiment. At the end of the experiment, calcium concentration was measured in each crab and the dry mass and condition index of each crab were determined.